feat!: "Syntax sugar" for pixels per meter measure

- Added meters function for better readability
- Adjusted tilemap_bundle transform
- Added 2nd floor in setup_world system

BREAKING CHANGE: Removed HALVED_PIXELS_PER_METER const

src/layout/container.rs

@@ -2,7 +2,9 @@ use bevy::prelude::*;
 use bevy_rapier2d::prelude::*;
 
 use crate::{
-    GameState, HALVED_PIXELS_PER_METER, PIXELS_PER_METER, inventory::{
+    GameState,
+    meters,
+    inventory::{
         ActiveInventory,
         Inventory,
         item::Item,
@@ -45,16 +47,16 @@ pub fn container_bundle(
     let image = asset_server.load(CRATE_CLOSED_ASSET);
     (
         Container,
-        Transform::from_xyz(position.x, position.y - HALVED_PIXELS_PER_METER, 0.),
+        Transform::from_xyz(position.x, position.y - meters(0.5), 0.),
         Sprite::from_image(image),
         Inventory::new(inventory_size),
         Observer::new(on_container_interact),
         Children::spawn((
             SpawnIter(items.into_iter()),
             Spawn((
-                Collider::cuboid(PIXELS_PER_METER, PIXELS_PER_METER),
+                Collider::cuboid(meters(1.), meters(1.)),
                 Sensor,
-                Transform::from_xyz(0., HALVED_PIXELS_PER_METER, 0.),
+                Transform::from_xyz(0., meters(0.5), 0.),
             )),
         )),
     )